The approaches described in this section are approaches that could be pursued, but not necessarily approaches that have been previously conceived or pursued. Therefore, unless otherwise indicated, it should not be assumed that any of the approaches described in this section qualify as prior art merely by virtue of their inclusion in this section.
A fleet of output devices may be managed by system administrators by sending management instructions directly to the output devices. To be able to send instructions to output devices, the administrators need to know at least the Internet Protocol (IP) addresses of the devices. The IP addresses may be automatically discovered via address discovery, which involves computer hardware and/or computer software transmitting discovery queries to devices, and requesting that the devices respond to the queries and provide their own IP addresses. The automated address discovery process is more efficient than a manual address discovery process because it is not as labor-intensive or error-prone as the manual process. However, even performing automated address discovery is generally time consuming —especially if it is performed in a communications network that includes thousands of output devices. In such networks, performing address discovery may place great demands on the network bandwidth and may be quite inefficient, and may also require a large amount of time.
Performing automated address discovery may be quite challenging in computer networks that include, for example, combinations of IPv4 and IPv6 subnetworks. In IPv4 networks, a network address may be expressed as a.b.c.d, where a, b, c and d each indicates an octet, or eight bits, of a network address. A large corporate network may be divided into many smaller subnets, and the first three or two octets of the network address are used to identify the subnet, while the last octet is used to identify a specific device. The resulting maximum address space for IPv4 subnetworks may theoretically address 4,294,967,296 devices. Discovering that many devices may be quite difficult and time consuming.
Even if a network uses less than 4 billion of IPv4 addresses, discovering all output devices in a IPv4 network may still be time consuming. For example, if a network uses a private addressing space that implements 9.b.c.d addresses, where 9 is a first octet reserved for private networks, the resulting maximum address space is 16,777,216. Performing address discovery on 16 million of network addresses may be still quite time-consuming. In fact, performing the discovery on 16 million addresses may be unnecessary if the network uses only a small part of that address space.
From a discovery point of view, performing address discovery in IPv6 networks is even more time-consuming and inefficient than in IPv4 networks. That is because the address space in IPv6 networks is larger than in IPv4 networks. In IPv6 networks, the IP addresses are represented using 128 bits (16 octets), rather than 32 bits as it is in IPv4 networks. A complete IPv6 address might look like 2001: 0db8: 0000: 0000: 0000.1f00: 0042: 8329. This can be abbreviated to 2001:db8:ff00: 42: 8329, but the resulting maximum address space is still enormous.
Even if a network uses a private IPv6 address space, the address space is still huge. For example, for private networks, fc00::/7 has been reserved, and if it is combined with a 40-bit prefix, it may provide private address spaces such as fde4: 8dba:82e1::/48 for an internal network, with 80 bits (10 octets) of addressing capability. That results in an enormous address space, and performing address discovery in that space would be extremely time-consuming. In fact, it may even stall data traffic in the network.
In networks that include both IPv4 and IPv6 subnets, performing address discovery may be just impractical. In IPv4 subnets, the discovery applications or systems may scan entire subnets (up to 254 devices for a single-octet subnet). However, with IPv6 subnets that typically have 64 bit-long addresses (eight octets), and thus 1.8×918 addresses, scanning the entire subnet may be impractical as it could take years to complete the scanning. Subsequently, discovering the IP addresses of devices in large and heterogenic computer networks using address discovery may be inefficient and impractical.